 	E_1   (double (+ E_0 Math/PI))]
     (try
      (sum [n inf-irrs]
-	  (let [phi_n (double (phi (node-positions n)
-				   (node-positions (upper-neighbours n))))]
-	    (cond
-	     (<= 0 phi_n phi_0)
-	     (+ phi_n
-		(/ (square (Math/sin phi_0))
-		   (Math/tan phi_n))
-		E_0),
-
-	     (<= (- Math/PI phi_0) phi_n Math/PI)
-	     (+ (- phi_n)
-		(/ (- (square (Math/sin phi_0)))
-		   (Math/tan phi_n))
-		E_1),
-
-	     :else 0)))
+       (let [phi_n (double (phi (node-positions n)
+				(node-positions (upper-neighbours n))))]
+	 (cond
+	  (<= 0 phi_n phi_0)
+	  (+ phi_n
+	     (/ (square (Math/sin phi_0))
+		(Math/tan phi_n))
+	     E_0),
+
+	  (<= (- Math/PI phi_0) phi_n Math/PI)
+	  (+ (- phi_n)
+	     (/ (- (square (Math/sin phi_0)))
+		(Math/tan phi_n))
+	     E_1),
+
+	  :else 0)))
      (catch Exception e
        Double/POSITIVE_INFINITY))))
 

      (* *gravitative-amount* (gravitative-energy layout information)))))

(defn- layout-force
  "Computes overall force _component_ of index n in the inf-irreducible elements."
  [layout inf-irrs n information]
  (let [part (mod n 2),
	n_i (nth inf-irrs (div n 2))]

;; Gravitative Energy and Force

(defn- phi
  "Returns the angle between an inf-irreducible node [x_1,y_1]
  and its upper neighbor [x_2, y_2]."
  [[x_1,y_1] [x_2,y_2]]
  (with-doubles [x_1, y_1, x_2, y_2]
